Idler arm



Dec. l, 1953 D. P. MARQUIS 2,660,905

IDLER ARM Filed Feb. 25. 1950 Patented lDee. l, 1953 UNITED STATES ATENT OFFICE IDLER ARM Donald P. Marquis, Ferndale, Mich., assignor to Thompson Products, Inc., Cleveland, Ohio, a

corporation of Ohio 12 Claims.

This invention relates generally to the steering mechanism of a dirigible vehicle and more particularly relates to an idler arm for a steer ingl linkage which incorporates a resilient elastic bearing permitting relative angular movement between two elements Without necessitating relative movement between bearing surfaces thereof.

Many automotive vehicles employ a parallelogram steering linkage in which a cross link is actuated at one end by a pitman arm operatively connected to the gear box of a steering column. The other end of the cross link is supported by an idler arm so as not to interfere with the straight longitudinal movement of the cross link by the pitman arm.

According to the features of the present invention, a bracket is attached to the frame of a vehicle and this bracket is provided with a housingr portion adapted to retain a resilient elastic bearing sleeve. The idler arm takes the form of a shaped bar of steel suitably bent to bring the linkage into the proper relationship with the bracket and is inserted within the bearing sleeve.

Since the housing portion of the bracket, the resilient elastic sleeve and the idler arm are in snug relationship with one another, the motion of the idler arm, which normally may be through an arc of approximately 90, will cause no movement between bearing surfaces but will produce only a torsional movement in the bearing sleeve.

It is, therefore, an object of the present invention to provide a bearing joint wherein relative rotation between elements of the vioint will produce a torsional movement in a resilient elastic sleeve or bushing but will not produce a relative movement between bearing surfaces.

Another object of the invention is to 'provide a bearing joint for an idler arm in a vehicular steering linkage which will substantially preclude the magnification or transmittal of rattling noises which originate in the steering linkage of a vehicle.

A further object of the present invention is to provide aV bearing joint for the idler arm of a vehicular steering linkage in which the elements are assembled in a predetermined fixed relationship so that binding and freezing between bearing surfaces is substantially precluded even though limited angular displacement of the idler arm occurs.

Yet another object of the present invention is to provide an idler arm assembly for a vehicular steering assembly which may be economically reduced number of simplified-V produced from a elements.

Still another object of the present invention 'l is to provide al bearing joint for an idlervarm of the vehicular steering assembly whichdoes not require lubrication.

Yet another object of the present invention is to provide a novel'method of manufacturing an idler arm and mounting the idler arm between a vehicular steering linkage anda ve' hicle frame, whereby the linkage may be supported in a proper geometric .relationship rela-' tive to a pitman arm connected to another portion of the vehicular steering linkage.

Many other features, advantages and addi-v. tional objects of the present invention will become manifest to those versed in the art upony making reference to the detailed description f which follows and the accompanying sheet of drawings in which:

I Figure 1 is a fragmentary top plan view'ofvv an automobile chassis havinga parallelogram-` type steering linkage equipped with an idler arm according to the present invention;

Figure 2 is an enlarged side elevational vie withl parts in section of the idler-arm of the 'present invention; and 1 i Figure 3 is a cross-sectional Viewv with parts' in elevation taken on line III-III of Figure 2.'

As shown on the drawing: f

The steering linkage is independently pivotally supported by wheel arms II, 'Il from the transverse beam I2 of an auv-tomobile frame which also includes side beams The wheels II), I0 `are rotated on stub-axles (not shown) pivoted on king pins I4, Id'f A vpair of steering Aarms I5, I6 extend rearwardly from the stub-axle assemblies anda pair'of tie rods.` I l, l1 are pivotally connected to eachof the` steering arms I5, I6 through a ball and V.socket type joint I8, I8. inwardly and are pivotally connected by means of ball and socket type joint I9, I9 to a cross link 2G pivotally connected at one end to a pit.v man arm 2| suspended on the rock shaft 22 of, gear box 23 carried on one ofl a steering column the side beams I3.

The tie rods I1, I l extend A steering column 24 may be rotated to actuate the rock shaft 22 and thereby swing the pitman arm 2| for longitudinal shifting of the cross link 20 whenever it is desired to selectively position the wheels I as in steering the vehicle,

In order to support the steering linkage in the proper geometric relationship and in order to properly transmit a steering load through a change of direction, an idler arm assembly indicated generally by the reference numeral 26 provides a movable joint between the other end of the cross link and one of the side beamsj I3 of the vehicle frame.

Referring more specifically to Figures 2 and' 3, the idler arm assembly 26 is shown as including a bracket 21 which in its prefabricated form preferably takes the form of' a flat plate-like piece of metal and is subsequently shaped to define a frame connecting portion 21a anda bearlngY housing portion 2117.

The frame connecting portion 21a, retains its flat shape and is provided with a pluralityof spaced apertures 28 through which suitable fasteners mayl be passed to secure the bracket 21 to the adjacent side beam |3 ofthe vehicle or to a suitable protuberance 29 appended thereto;

The idler arm proper, indicated by the reference numeral' 3|), may comprise an ordinary piece of' steel bar stock suitably bent into the general configuration of a crank having oppositely extending parallel arm portions 3ndy and 30h connected by a central arm portion 39e to bring the linkage into proper relationship with the bearing house in the bearing housing portion 21h.

A resilient elastic sleeve-like bushing 3| snugly surrounds aportionofthearm 30a, ofthe idler arm 3U adjacent one end thereof and serves as a bearing between the idler arm 30 and the bearing housing portion 21h when a pair ofv ear portions comprising the bearinghousing portion 2lb are curled to form a tubular bearing retainer, the cross-section of which being substantially circular. Y

As may be noted on the drawings, the respective abutting edges of' the bearing housing por'- tion 21h denne male and female interlocking mating means such as a keystone-shaped lock stitch 32 so that the bearing housingY portion 2lb may be retained in a tubular shape and so that the bushingV 3|, the idler' arm 3U and' the bearing housing portion v2lb of7 thev bracket 21 may be placedin a snug and relatively predetermined angular relationship with respect to one another.

It will be appreciated that the idler arm when subjected to ordinary conditions of use will normally be moved, through an arev of approximately 90', however,` with thev bearing ofvr thepresentY invention there will beno relative movement be-A tween bearing surfaces since the angular dis placement of the idler arm 30 will be completely accommodated by' torsional movement in the bushing 3l.

Because of the frictional engagement effected betweenr the idler arm. 30, thev bushingv 3| and the bearing housing portion 21h of they bracket' 21., there will ordinarily be no axial. movement of the arm portion 30a` of the idler arm 3|! relativev to the bracket 21. Nevertheless.. for purposes of safety, the end of the arm portionr 30er,Y

ofthe idler arm 30 is provided withy a threaded. portion 33 which receives a nut 3|!V and. which may be employed to maintain a washer 36 in abutting relationship to the bearing, housing. portion 21h. The nut 34 may be locked in a predetermined axial position on the threaded portion 33 by means of a cotter pin 31.

At the other end of the idler arm 30, a rubber bushed sleeve bearing assembly, indicated generaflly by the reference numeral 38 is provided to effect a pivotal connection between the idler arm 30 and the cross link 20. This assembly 38 includes a bearing sleeve 38a; receiving. the end 30h of the arm 30 in a rotatable relation, a rubber bushing 38h surrounding the sleeve and an eye end housing 38o on the end of the cross link 20. A rubber washer 38d overlies the top of the housing 38e and is covered by a metal cap 38e.` This connection serves to snub the rotation ofthe cross link 2D about the axis of the arm portion 30T) of the idler arm 3U while permitting misalignment which produces deflection of the resilient elastic bushing 3|. It will be appreciated that the steering motion occurs beu tween the metal sleeve bearing 38a, and the idler arm 30.

In order to-keep the-bearing 38E in correct axial` alignment on the arm end 30h, the arm 33D! of' the idler arm may be pinched to forml ears- 39 and the arm portion 3022' has a threaded end' 33d receiving a metal. washer 38j underlying'tlle` housing 38e and a castellated nut and cotter pin locking means indicated generally by thereinerence numeral 40. TheY nut is. drawn up. on

the threaded end 30d to abut the cap against" the ears 39.

It will be apparent. that the construction described permits the employment of` ordinary forms of commercially availablefbar stock which" require no additional finishing opera-tions on thel arm portion 30a. Moreover', the provisionofithe resilient elastic bushing 3 functioningaszabearing between the bracketV 21 and the idler:` arm*- 30 results in a permanent assembly' which: re-y quires no lubrication and which substantial-ly precludes the magnification or transmittal of' rattle noises which frequently originate in the elements of a steering linkage.

y Although various. modicationsf'might be sugv gested to those versed in the art,. itl should be understood that4 I do not wish to bey limited to the precise details described connection'.r with'A the preferred embodiment herein' set forth by wayA of illustrative example; Accordingly, it is in.- tended' that the scope ofV this patent extend to all such embodiments as reasonably and properly come within the scope of; my contributionto the art.

l'. claim as myiinvention:

1. In a vehicular steeringy linkage, a metal ban bent into the general configuration of a crank and formingA an idler'arm, a resilient', snug-it ting, sleeve-like bushing surrounding. a relatively angularly displaceable portion. of. the armnear one end thereof, a-relatively stationary bracket` havingy aportion thereof curled. snugly aroundthe bushing; to form a tubular retainer therefor.r

which is substantially circular in cross-section,- the assembled relationship of the elements. be,-

ing such that rotation. of. the arm. element relative to saidl bracket willproduce only torsional. movement in the bushing but no relative movement. between the contacting bearing, surfaces.

2. In a steering linkage, a piece of metal bar'Y stock formed into the general configuration of'vv a crank and comprising an idler arm,y a resilient elastic bushing surrounding a relativelyr angu..

larly displaceable portion of. the idler arm near one end. thereof, a. relatively stationary bracket. havng a pair of ears curled snugly around the bushing'to form a tubular retainer substantially circular in cross-section and loc-king elements dened by the ears to retain the housing in tubular shape and to insure that the'assembled'relationship .of the elements willA produce only torsional movement in the.` bushing upon angular displacement of the idler arm relative-to the bracket.

3. In a vehicular steering linkage a metal bar shaped substantially tothe general configuration of a crank and comprising an vidler arm, aresilient, snug-fitting, sleeve-like bushing surrounding a relatively angularly displaceable portion of the idler arm, a flat plate-like bracket element, apertures defined by a portion of the bracket element to pass fastening means therethrough, another -portion of the bracket element being curled snugly around the bushing to form a tubular housing therefor, fastening means connecting the bracket to the frame of the vehicle, a bearing on the other end of the idler arm and means connecting said bearing to a link of the steering linkage, said bushing arranged to accommodate relative angular movement between the idler arm and the bracket.

4. In a steering linkage of a vehicle, an idler arm comprising a metal bar shaped in the general conguration of a crank, a resilient sleeve snugly surrounding one arm of the crank near an end thereof adapted to be relatively angularly displaced and a. bracket having a tubular portion snugly surrounding the sleeve, rotational movement of the idler arm relative to the bracket producing only torsional movement in the sleeve.

5. In a vehicular steering linkage, an angularly displaceable idler arm, a resilient sleeve snugly surrounding a portion thereof and a bracket adapted to be connected to a vehicle part relatively stationary with respect to said idler arm, said bracket being formed from a substantially nat plate and having a tubular housing portion defined by two oppositely extending ears curled to a substantially circular cross-section, said tubular housing portion snugly receiving the resilient sleeve so that rotational movement of the idler arm relative to the bracket will produce only a torsional movement in the sleeve.

6. In a vehicular steering linkage, an idler arm, a resilient sleeve snugly surrounding a portion thereof and a bracket, said bracket being formed from a substantially flat plate and having a tubular housing portion defined by two oppositely extending ears curled to a substantially circular cross-section. said idler arm and said bracket being relatively angularly displaceable, said tubular housing portion snugly receiving the resilient sleeve so that rotational movement of the idler arm relative to the bracket will produce only a torsional movement in the sleeve, the abutting edge portions of the ears dening mating elements of a male and female locking structure to retain the housing portion of the bracket in a tubular shape.

'7. In a vehicular steeringlinkage, a vehicle frame idler arm, a resilient elastic material surrounding one end of the idler arm, a housing portion of a bracket member enclosing the resilient elastic material, fastening means connecting the bracket member to the side beam of the vehicle frame, a bearing on the other end of the idler arm and connecting means between the linkage and the bearing, whereby angular displacement of the idler arm relative to the bracket will produce only a torsional movement in the resilient elastic material.

8. In a vehicular steering linkage, an idler 'arm assembly comprising an idler arm, a krubber-like bearing on one end thereof, a bracket dei'ining a housing portion snugly enclosing the bea-ring, locking means between the bracket and the idler arm to preclude relative axial movement therebetween, a' rmetal bearing carried on the other end of the idlerv arm and a cross link connected to the'metal bearing to angularly displace 4'the idler arm, whereby angular displacement of I'the idler armwill produce torsional` movement only in the rubber-like bearing.

9. In a structure for movably connecting the free end of a cross link on parallelogram-type vehicular steering linkage to the frame of the vehicle, a generally crank-shaped idler arm, a sleeve of resilient elastic material surrounding a portion of one end thereof, a bracket enclosing the resilient elastic material, means connecting the bracket to the frame, a bearing at the other end of the idler arm and bearing to the free end of the cross link, whereby angular displacement of the idler arm will produce torsional movement only in the resilient elastic material and steering motion will be accommodated between the bearing and the cross link.

l0. In a steering linkage of a vehicle, a vehicle frame idler arm, frame fastening means at one end of the idler arm including a resilient sleeve snugly surrounding a portion of the idler arm adapted to be relatively angularly displaced with respect to the vehicle frame, said frame fastening means further including a bracket having a tubular portion snugly surrounding the sleeve, and pivotal connecting means at the other end of said idler arm to connect said idler arm to the vehicular steering linkage and effecting movement of the idler arm relative to the bracket to produce only torsional movement in the sleeve.

l1. In a vehicular steering linkage, an angularly displaceable idler arm, a resilient elastic, sleeve-like bearing carried at one end of the idler arm, a vericle frame bracket having a tubular housing portion surrounding the resilient elastic bearing and clamping said bushing and said idler arm in bonded assembly, locking means between the idler arm and the bracket to preclude relative movement axially with respect to said bearing, and connecting means at the other end of said idler arm for connecting said arm to the vehicular steering linkage, and for rotating said idler arm relative to said bracket within the elastic limits prescribed by the elasticity of the bearing.

12. In a vehicular steering linkage, an angularly displaceable idler arm, a resilient elastic bearing surrounding one end of said idler arm. a vehicle frame bracket member having a housing portion for connecting said one end of said idler arm to a vehicle frame, said housing portion and. said idler arm being connected by said resilient elastic bearing only, and a bearing at the other end of said idler arm for connecting said idler arm to the vehicular steering linkage and for angularly displacing said idler arm relative to the bracket against the torsional resistance of said resilient elastic bearing within the elastic limit of the resilient elastic material of said resilient elastic bearing.

DONALD P. MARQUIS.

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